The invention relates generally to a winding cone for a garage door, and more particularly to a winding cone adaptor capable of use in a low head room or cramped environment and used to increase the tension of a garage door spring.
Overhead doors, most commonly seen and known as garage doors, are used in many commercial and residential applications. Installed with multiple hinged sections on several guiding tracks, the doors can be raised and lowered with the help of pulleys, cables and torsion springs. A horizontal shaft (or torsion rod) extends near the top of the door opening and the pulleys are typically positioned on and near the ends of the shaft. The cables attach near the bottom of the door and wrap around the pulleys. The torsion springs surround the shaft and allow the door to be easily opened and closed by counteracting the weight of the door. A frusto-conical piece called a winding cone is designed to engage an end of the torsion spring and to be fixed to the shaft. Engagement with the torsion spring is typically accomplished using annular grooves on the frusto-conical surface that engage coils of the torsion spring. Fixation to the shaft is typically accomplished with a set screw that can be tightened on the winding cone to securely engage the shaft.
Tension in the spring is necessary to easily raise the door. To impart the needed tension in the spring, installers make use of holes in the winding cone to insert winding rods. By placing a winding rod into one of the holes in the winding cone, force can be exerted on the end of the winding rod to rotate the winding cone, thereby increasing tension in the spring. Since winding cones typically have four such winding holes, after rotation of the winding cone has reached a limit due to the radial winding rod, another winding rod is inserted into another winding hole. The first winding rod is removed to permit additional rotation of the winding cone and spring. The steps are then repeated until the spring is sufficiently wound.
Several common situations arise that make it difficult or impossible to properly impart the desired tension on the torsion spring. A confined area in which to maneuver the radial winding rods can result from low headroom or an immovable obstruction in the vicinity of the winding cone. Since winding cones typically have only 4 winding holes equally spaced around the outside surface, the winding cone must be rotated 90 degrees in order for the next winding hole to be accessible for another winding rod. If 90 degrees of rotation is not plausible, tensioning of the spring becomes very difficult. It is to the deficiencies in the prior art that the present invention is directed.